Quick question with (probably) a quick answer!

[ov]

Is there a "rule of thumb", as to how many clients one should plan pr 802.11n accesspoint?
(I'm referring to 1142's and 3502's)

On a 802.11b/g acesspoint, i've been using 20-25 as max client count.

[Surendra BG]

Hi,

Yes.. you are right.. its recommended not to have more than 25 clients on a AP.. The AP will support more but you will face heavy bandwidth problem

Regards

Surendra

[ov]

Thank you for you answer..but its not what i'm after.

I know i'm right with 20-25 users on an 802.11b/g accesspoint.. (1131/1242..)

Thats why i asked what the number would be on an 802.11n accesspoint. (1142/3502..)

[Surendra BG]

its the same on all the APs...

Regards

Surendra

[ov]

What you are saying does not add up at all.

This is quoted from Ciscos own doc "Key Performance Benefits Of 802.11n"

"

Suppose we were to replace these three 802.11g access points with three next-generation, 802.11n access points. The system-level bandwidth in the classroom would increase substantially and more than 96 students (32 users per access point) would be able to connect to their wireless network and expect to have a consistent application experience.

"

http://www.cisco.com/en/US/solutions/collateral/ns340/ns394/ns348/ns767/white_paper_c11-513840_ps10092_Products_White_Paper.html

Here 32 clients is mentioned. The text also refers to an application that requires 5 Mbit of bandwidth, to deliver at a good quality, which these accesspoints clearly do.

Perhaps this wasn't a question with a quick answer after all.

[George Stefanick]

Its a rule of thumb. Its not to say you CANT get more.

But here again. You need to design around what your needs are. For exmaple, suppose you have 30 users in a room and they're all performing very light web browsing. Perhaps 1 or 2 aps is good. But now take that same room with 30 users that are all doing video, voice, smartphone, etc .. Well you need to design for that ...

So the genral rule of tumb and I agree with Sur is still 20 - 25. Let me tell you why I think so ... The 20-25 have been the rule for a long long time. Even though 802.11n can afford you quicker speeds which results in less use of teh medium. However, we are seeing a ton more clients than ever before. Before, we had laptops mainly. Today, we have phones, ipads, tablets, laptops, cameras and the list goes on...

So for me ... i still use the 20-25 clients as well ...

[ov]

Well, i understand what you are saying. However, yes we have an new world regarding the

potential amount of new wireless clients out there. But that is actually not relevant to what i'm asking about.

The classrom referred to in the document mentioned earlier, has 96 students and three accesspoints.

Each accesspoint handles 32 clients (phones, pdas, laptops..whatever, not relevant), with a sustained throughput

of approx 5 Mbit pr client. All according to Cisco. And i have to say that 4-5 Mbit pr client isn't bad, its

actually quite good.

If 20 clients are happy with the throughput on one 802.11b/g accesspoint, wouldnt it be logical to assume that

30 clients would be happy with the same on a 802.11n accesspoint? (As long as the increased bandwidth supports

it of course). This is why i would think that "the rule of thumb" i asked about would expand a bit on 802.11n accesspoints. 

Maybe someone could point me in the direction of some good documentation around client planning in 802.11n

networks?

[George Stefanick]

Yes, but this is only relevant to what data you will be pulling down. Regarless of what docment you read and what it states you have to understand your planned use. If you were to design a wired network and have 5 users web surfiing wirh 10 gig uplinks its over kill, right ... Same thing with an AP. Think of the 802.11b/g as a 100 meg hub. The 802.11n as a gig hub.

yes, you can get more users IF they all support 802.11n.

Have you thought what if a 802.11g device gets on your 802.11n AP? Your model is now shot becuase you have to account for legacy devices. There is just WAY to many things to account for ... Any Cisco document may only reflect "cisco" marketing as well.

I have 5 devices on wireless 802.11n pulling GIGs of PACs images. This throws that model you speak of out of the water. You need to ask yourself, what traffic will these clients generate. Theory is nice, but real world is a different ball game.

I might suggest some light reading on 802.11n and understand how it works. This may help you with your efforts in understanding client load.